In this 1873 abridgement of their Treatise on Natural Philosophy, Peter Tait and William Thomson, Lord Kelvin, intended their work to be accessible to students with a basic knowledge of algebra, geometry, and trigonometry. In the vein of Isaac Newton's 17th-century Principia Mathematica, as a summation of the state of "natural philosophy," this is a synthesis of physics that scientists, building upon Newton's work, envisioned at the end of the 19th century. It is perhaps most interesting as one of the last such treatises before the advent of relativity and then quantum physics, which considerably altered and enlarged science's concept of the natural world.